The present invention is generally directed to toners, and toner processes, and more specifically to wax containing colorants, and aggregation and coalescence processes for the preparation of toner compositions. In embodiments, the present invention is directed to the economical chemical insitu preparation of toners, and wherein toner compositions with an volume average diameter of from about 1 to about 25, and preferably from 1 to about 10 microns in volume average diameter and narrow GSD of, for example, from about 1.15 to about 1.25 as measured on the Coulter Counter can be obtained, and which toners contain an optional non functionalized wax component, such as a low molecular weight wax, with from for example, a Mw of from about 800 to about 20,000, (about includes values in between throughout) and further containing modified functional waxes, such as polyalkylenes, like suitable polyethylenes, and polypropylenes, or hydrocarbons, each containing functional groups such as halide, like fluorine, amide imides, esters, quaternary amines, carboxylic acid, mixtures thereof, and the like on the polymer backbone, thereby permitting for example, substantial complete incorporation of the functionalized wax into the toner particles. The functionalized waxes selected and present in various suitable amounts, such as from about 1 to about 20, and preferably from about 2 to about 10 weight percent are available from a number of sources, such as Petrolite, Dow Corning, E. I. DuPont, S.C. Johnson Wax, and Sanyo Chemicals of Japan. The complete total functionalized wax incorporation (contrasted to of less than complete incorporation, for example from about 20 to about 40 percent incorporation of the nonfunctionalized waxes of the prior art resulting in release and stripping problems during image and toner fusing) into a host toner resin is important for release purposes when such toners are selected for known electrophotographic imaging processes.
With the processes of the present invention in embodiments, small average toner particle sizes of, for example, from about 3 microns to about 12, and preferably about 5 microns result without resorting to classification processes, and wherein narrow toner geometric size distributions are achievable, such as from about 1.16 to about 1.30, and preferably from about 1.16 to about 1.25. High toner yields are also obtainable with the processes of the present invention, such as from about 90 percent to about 98 percent.
In reprographic technologies, such as xerographic and ionographic devices, toners with volume average diameter particle sizes of from about 9 microns to about 20 microns are effectively utilized. Moreover, in some xerographic technologies, such as the high volume Xerox Corporation 5090 copier-duplicator, high resolution characteristics and low image noise can be attained utilizing the small sized toners of the present invention with, for example, an volume average particle of from about 2 to about 12 microns and preferably less than about 7 microns, and with narrow geometric size distribution (GSD) of from about 1.16 to about 1.3. Additionally, in some xerographic systems wherein process color is utilized, such as pictorial color applications, small particle size colored toners, preferably of from about 3 to about 9 microns, are needed to avoid paper curling. Paper curling is especially observable in pictorial or process color applications wherein three to four layers of toners are transferred and fused onto paper. During the fusing step, moisture is driven off from the paper due to the high fusing temperatures of from about 130 to 160.degree. C. applied to the paper from the fuser. Where only one layer of toner is present, such as in black or in highlight xerographic applications, the amount of moisture driven off during fusing can be reabsorbed proportionally by the paper and the resulting print remains relatively flat with minimal curl. In pictorial color process applications wherein three to four colored toner layers are present, a thicker toner plastic level present after the fusing step can inhibit the paper from sufficiently absorbing the moisture lost during the fusing step, and image paper curling results. These and other disadvantages and problems are avoided or minimized with the toners and processes of the present invention.
Lower toner fusing temperatures, such as about 120 to about 150 degrees Centigrade, and which fusing temperatures can be achievable with the toners of the present invention, minimize the loss of moisture from paper, thereby reducing or eliminating paper curl. Furthermore, in process color applications and especially in pictorial color applications, toner to paper gloss matching is important. Gloss matching is referred to as matching the gloss of the toner image to the gloss of the paper. For example, when a low gloss image of preferably from about 1 to about 30 gloss is desired, low gloss paper is utilized, such as from about 1 to about 30 gloss units as measured by the Gardner Gloss metering unit, and which after image formation with small particle size toners, preferably of from about 3 to about 5 microns and fixing thereafter, results in a low gloss toner image of from about 1 to about 30 gloss units as measured by the Gardner Gloss metering unit. Alternatively, when higher image gloss is to be generated, such as from about 30 to about 60 gloss units as measured by the Gardner Gloss metering unit, higher gloss paper is utilized, such as from about 30 to about 60 gloss units, and which after image formation with small particle size toners of the present invention of preferably from about 3 to about 5 microns and fixing thereafter results in a higher gloss toner image of from about 30 to about 60 gloss units as measured by the Gardner Gloss metering unit. The aforementioned toner to paper matching can be preferably attained with small particle size toners such as equal to or less than about 7 microns and preferably about 5 microns, and more preferably from about 1 to about 4 microns, whereby the pile height of the toner layer or layers is considered low.